The present invention relates to a device for positioning a copy master in the focal plane of a copying apparatus.
In automatic continuous copying installations, e.g., photographic printers, the copy master is usually held in the copying position on the master stage by means of a hold-down plate, with the plate in most cases being equipped with lead-in bevels to prevent catching parts of the master that protrude from the transport path on the plate. Such hold-down plates operate satisfactorily if relatively long, continuous film strips are involved. In the case of noncontinuous copy masters, if for example individual images or short film strips are lined up at spaced intervals on a carrier strip, as is usually done with reorders, these hold-down plates have a disadvantage. More particularly, the copy master, at least at its leading edge which in the copying position is located exactly in the area of the lead-in bevel, is not held down and therefore the normally present curvatures and warps of the master are not eliminated, which in turn leads to defective copies.